Bujrgess



W. S. BURGESS.

AIRPLANE CONTROL SURFACE OPEMTING BRACE.

APPLICATION FILED M131. may

Patented Nov; 9, 920.

F165. an'mm W; LLIAM Smzune DUEGESS.

. NmW z s Specification of Letters Patent.

Patented Nov. 9, 1920.

Application filed May 31, 1918. Serial No. 237,460.

T whom it may concern:

Be it known that .1, WILLIAM a (:itiAen of the United States, residing at Marbleln-rad, in the county of Essex and State of l\lassachusetts have invented certain new and useful Improvements in Airplane-Control-SurfaceOperating Braces, of which the following is a specification.

This invention relates to airplane details. 10 The particular part or element of the airplane to which the inventor has reference that part known as the rudder operating brace or yard arm. Such part ordinarily comprises opposed lever arms or horns, con- 5 trol leads, and Wire stays which brace the control surface by connection with the lever arm at one end and with the control surface 'at the other. Accordingly as the control leads are manipulated and placed under tension the resulting stress is uniformly distributed over an extended area of the surface. This same result is obtained by the control surface operating brace of the present invention. The means however of olr 5 taining this end is different. The use of stay wires is completely eliminated; also the use of separate lever arms or horns. Instead there is provided a plate having substantially equal portions of its area arranged upon opposite sides of the control surface. The plale itself is preferably of triangular form and of a length suflicicnt to carry its base end forwardly beyond the. front beam of the control surface and its apex end rear- \vardly beyond the trailing beam thereof. This not only strengthens the control sur face transversely but provides'for thelimi nation of the stay wires. The base end or leading edge of the plate is reinforced. 40 throughout the major portion of its length and the "ontrol leads connected at the base angles. 'lhr bracing means not only prcvent transverse distir'lion of the plate but it strcnglhens it at tho leading edge and in the direct \ir-inil'. of lhe points of attach ment of the control Lads. Further constructional features of the operating brace or yard-arm will be hereinafter set forth.

S. BURGESS,

It sulliricut to state that he Hli2$-*ll'll!'fl()ll 0f the plateis such that the ontr l zrlncc j she. pduncd without undue r1 fulfil" .Illil at ;a point where maximum strength is required.

Of the drawings:

Figure 1 is a plan view of the rudder o J- crating brace showing its attachment to l ie rudder.

Fig. 2 is an enlarged transverse sectional view of the rudder.

Fig. 3 an edge View and Figs. 4, 5. 6 and T are enlarged sectional views on the lines 4-1-, 5-5, 6-6 and 7-'? of F ig.

The invention, although described as a rudder operating brace. is equally as well applicable to any and all control surfaces of an. airplane. it is intended to supplant the lever arms or horns of airplane control surfaces.

In F ig. l the rudder operating brace designated in its entirety by the numeral 10 is shown as attaclu-nl to the rudder ll of an airplane (not shown). The rudder is in turn mounted in direct continuation of the vertical tin or stabilizer 12 to Which it is hinged as at 13 for lateral swinging movement. The rudder itself comprises the usual front beam l-l and rear beam 15, th latter in the embodiment illustrated lying somewhat ahead of thetraijling edge of the rudder. \Veb strips 16 "eirtend at right angles to the beams 14 and 15 and with cap strips 17 constitute the rudder frame-work. In the BITIlJOdllllBlll; illustrated only the web strips and cap strips lying in the immediate vicinity of the control brace are shown.

The control brace or yard arm in'its preferred embodiment comprises a substantially triangular plate 18 having lightening holes 19 of suitable size formed in it. The trianglllar form of the plate is that of an isosceles triangle. the base of the triangle being forwardly located to biscct the front V beam 14 of the rudder. Substantially equal portions of the total area. of the plate 18 he upon opposite side's of the rudder as indicated in Fig. :2.

At the base end of of the control base, 60

the triangular plate ]H a recess or opening-'20 is provided. The size of this recess is dcpendentvupon the cross scctirmal area. of the front rudder beam 14. The rudder beam is fitted in'the recess and the late 18 is attached to the beam by oppo angle plates 21. These angle lates are 0 posednot only with respect to t 1e plate 18 ut with respect to the beam 14 as well.

Another and somewhat similar opening 22 is formed in the plate 18 at or near its apex end. Through this opening the rear. or trailing rudder beam 15 extends. As an attaching means cars 23 are struck out from the plate '18 to lie flat against the beam 15 to which they are fastened as indicated at 24. There is thus provided a fastening at the leading edge of the rudder (to the front beam 14) and also at a point distantly removed therefrom. The result is that the rudder is transvelsely braced and the operatin stress occasioned by the manipulation of t e control leads distributed over an extended area of the rudder.

The control leads, designated as 25,.are'

fastened respectively at opposite edges of the plate 18 and preferably at the base an gles thereof. From the points of attachment of the control leads inwardly the plate 18 is reinforced by opposed metallic tubing 26 split longitudinally and brazed to the lead ing edge of the plate. This reinforcing means effectually prevents transverse dis tortion of the plate and strengthens it latorally out from the beam 14 to the points of attachment of the control leads where added strength is most needed. At the points of attachment of the leads 25 with the plate 18 washers 27 are provided. These washers are brazed on and preferably provided upon the opposite faces of the plate to strengthen it and. at the same timeto constitute eyes for the attachment of the control leads 25. If desired, the metallic tubing 26 may be pro 'vided with a filler or core 26' for added strength. 7

The plate, it will be noted, is constructed in one piece and extends uninterruptedly through the rudder surface. For that P01" tion of its area, defined by the thickness of the rudder, it is faced by the web strip 16 and cap strip 17 the web strip being riveted to the plate as indicated at 28 at several points tostrengthen the rib and better dis tribute the operating strains over the full area of the rudder.

If desired, the plate 18 may be covered with suitable fabric so that the lightening holes 19 will not be apparent. This would tend to minimize head resistance although the fabric, in the drawin s is notshown. Moreover, the length of t m plate may be increased and its a ex end carried back to the trailing edge 0 the rudder. This how-- ever is unnecessary .where .the rudders are provided with what are designated as trailing beams which are forwardly removed from the trailing edge of the rudder.

While I have described my invention in detail in its present preferred embodiment. it will be obvious to those skilled in the art after understanding m invention that various changes and modi cations may be made therein without departin from the s irit or scope thereof. I aim in t e appendet claims to cover all such modifications and changes.

What is claimed is: i

1. In an airplane, the combination with a control surface, of an npelutii)" brace extended through the control surfiurv at substantially a rlght angle, said o wrating luluhaving itsleading edge concuvwl. flu: w-int of maximum concavity lying closely .Nl jacent the leading edge of the control EH1- face.

2. An operating brace for airplane co, trol surfaces comprising a plate extended through the control surface for pri-wntation edge-wise to the air, the depth of the plate in a fore and aft direction exceeding its width and being at least cqunl'to the dis tanoe between the leading and trailing beam of the control surface, said plate at opposite sides of the control surface and along its leading edge being extended forwardly and outwardly at an angle.

3. An airplane control surface opera brace comprising a sul'isti'mtially triangi. r plate having equal portions of its area 3 posed respectively at opposite sides o: 11-. control surface together with means rein forcing the base end of the plate throughout the major portion of its length whereby the plate in its entirety is held against trans verse distortion.

4. An airplane control surface operating brace comprising a substantially triangular plate extended through the control surface and having substantially equal portions of its area arranged respectively at oppositisides thereof, the marginal edges of the plate diverging inwardly from point di rectly opposite the leading r'lgc of the control surface, the degree of divergence in each instance being such that the edges of the plate define angles less than a right angle.

5. In ail airplane, the combination with a control surface, of an. operating brace extended through the. control surface t sub stantially a right angle, said operating brace having its ends recessed to receive structural. elements of the control surface.

6. An airplane control surface operating brace conmrising a plate having substan tially equal portions of its area arranged respectively at opposite sides of the control surface, said plate being provided at or near brace comprising a plate, having substantially equal portions of its area. arranged respectively at opposite sides of the control surface, said plate being provided at,or near its apex end with a recess or opening Within which the trailing beam is fitted.

8. An airplane control surface operating brace comprising a plate having substantially equal portions of its area arranged re spectively at opposite sides of the control surface, said plate being provided with recesses or openln' respectively at or near its leading edge an apex nd for the reception of the front beam and lbaiiihg beam of the control surface respectively.

9. An airplane control surface operating brace comprising an isosceles triangular plate having substantially equal portions of it: area arranged respectively at opposite sioes 'of the rudder, said plate having a grad- 2oually decreasing width from front to rear and an over-all length sutfieient to overlap respectively the front beam and the trailing beam of the control surface, means reinforcing the base end of the triangular plate to prevent its transverse distortion, and means for fastening the plate to the control surface at its base end and apex end respectively.

10. An airplane control surface operating brace including in combination with the beams and ribs of the control surface, a substantially triangular'plate having its apex end extended beyond the trailing beam and its base end extended beyond the leading beam of the control surface, said plate, intermediate its base end and apex end being reinforced longitudinally by the webs of the control surface.

11. Airplane control surface operating equipment including a one piece metallic plate extended through the control surface for projection beyond its opposite faces.

In testimony whereof I hereunto afiix my signature.

WILLIAM STARLING BURGESS. 

